Union queries from different databases in Laravel Query Builder

Question

I have two similar tables in two different databases. Both tables have a column with a date and one with email addresses. Though the column names are not the same. As resul

Answer 1

You can't use different connections, but you still can do it providing the db name explicitly:

$q1 = DB::table('db1.contacts')
       // where(..) or anything you need here
       ->select('mail_address as email', 'date as created_at');

$q2 = DB::table('db2.contacts')
       // like above
       ->select('email', 'created_at');

$result = $q2->union($q1)->get();

Answer 2

You cannot do a UNION query across connections. You'll have to do it as two separate queries:

$emails1 = DB::connection('db1')->table('contacts_1')
             ->selectRaw('mail_address as email, date as created_at')->get();

$emails2 = DB::connection('db2')->table('contacts_2')
             ->select('email', 'created_at')->get();

$emails = array_merge($emails1, $emails2);